Field Sobriety Test Flaws

Posted by Jarrett P. AmbeauMay 09, 20200 Comments

Field sobriety test flaws Louisiana The Ambeau Law Firm police officer administers a field sobriety test to a man suspected of drunk driving

The System Is Far from Perfect

Arrested for DWI? Don't worry, there are several reasons why a police officer may believe you were driving while intoxicated that can be challenged in court. Besides the fact that you may have swerved out of your lane or didn't fully stop at a stop sign, among other elements of probable cause to pull you over, an officer may believe you were intoxicated because you failed to “pass” one or all of the Standardized Field Sobriety Tests.

Standardized Field Sobriety Test Facts

The Standardized Field Sobriety Test (SFST) is a battery of three tests intended to determine if a driver is impaired. These tests establish probable cause for an officer to arrest a driver for DWI. As such, officers may intentionally or unintentionally administer these tests incorrectly, meaning your DWI accusation may result from reasons other than your alleged “intoxication.”

The following describes the three SFSTs:

Horizontal gaze nystagmus (HGN) test: This is the first test you will take following your traffic stop. This test examines involuntary eye jerking that occurs when you gaze to the side (horizontally). An officer may use a pointed object such as a pen, penlight or tip of a pencil to track your eye movement; if they notice your eyes don't track the object smoothly and they jerk at a lower angle than they would if you were sober, you may be charged with DWI.

Walk-and-turn test: This divided-attention test measures your mental and physical abilities. The officer will give instructions on how to complete the heel-to-toe test, and you will be required to complete this test while simultaneously following instructions from the officer. You are required to take nine heel-to-toe steps in a straight line and then turn in the opposite direction to complete the remaining nine heel-to-toe steps.

If you cannot keep your balance or don't follow the instructions properly, the officer may believe you are impaired.

One-leg stand test: This divided attention test requires you to stand on one leg while the other leg is raised about six inches off the ground. While doing so, you will be asked to count in thousands (one-one thousand, two-one thousand, etc.). If you sway while balancing, put your foot down, hop or use your arms to balance, an officer may believe you're intoxicated.

Why You Cannot Trust These Tests

Underlying medical conditions, weather conditions, the location in which the test was administered, and other factors may interfere with a successful outcome:

Horizontal gaze nystagmus (HGN) test

  • Prescription drugs may hinder your nystagmus
  • Optokinetic Nystagmus can give officers a false positive
  • If you're pulled over on the side of a road, bright headlights and fast-moving cars could impact your results
  • The officer's bias may interfere with their ability to conduct the test objectively
  • Improper explanation of test instructions may cause you to fail through no fault of your own

Walk-and-turn test & one-leg stand test

  • Poor weather conditions such as rain, wind and snow could interfere
  • Improper footwear such as heels and sandals could impede your ability
  • Underlying medical conditions such as vertigo, poor eyesight, joint pain, leg injuries, etc. can give officers a false impression that you're under the influence
  • Faulty administration of test instructions could cause you to mess up even when it's the officer's fault
  • The officer's preconceived notions that you're “intoxicated” may cause them to arrest you for DUI regardless of the test results

If you believe you were wrongfully accused of DWI as a result of your field sobriety test results, contact our defense attorney at The Ambeau Law Firm by calling (225) 330-7009! We can work to prove that your accusation occurred through no fault of your own, but rather conditions such as weather, underlying health issues, road surfaces and the officer's improper administration techniques.

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